Process of refrigeraiton.



F. E. NORTON. PROCESS OF REFRIGERATION, APPLICATION FILED IAI. 3. "l5.

1,264,845. Patented Apr. 30, 1918.

1 UNITED STATES PATENT. OFFICE.

FRED E. NORTON, OF WORCESTER, MASSACHUSETTS. ASSIGNOB TO JEFFERIES-NOETON CORPORATION, A'COBPOBATION OF DELAWARE.

PROCESS OF REFRIGERATION.

To all whom it may concern:

Be it known that I, FRED E. Non'mN, a

citizen of the United States residing at Worcester, in the county of Worcester and Commonwealth of Massachusetts, have invented a new and useful Improvement in Processes of Refrigeration, of which the following, together with the accompanying drawings, is a specification.

The present invention relates to processes of refrigeration, and has particular reference to improvements in processes of this class which, in general, contemplate the attainment of extremely low temperatures by the expansion of a gaseous fluid. The low temperatures attained in the present process, in common with the processes previously ractised, may be used, ing extreme refrigerative eflects; or the process may be carried on for the purpose of liquefying, in whole or in part, the gas, and if desired, this liquefaction, if the gas be a mixed gas, may be employed in connection with suitable distillation agencies to effect the separation of the gas into its constituent elements. Moreover, as will be shown, the process may with advantage be utilized for the cheap and efficient pro action of ower in a form available forthe production of useful work.

The process of the present invention contemplates the attainment of marked improvements in efiiciency and capacity over refrigeration systems using the processes heretofore known; the principles of the invention and the various steps employed in the application of said grinciples to the accomphshment of the esire results, are fully set forth in the followin description and pointed out in the annexe claims reference being had to the accompanyin rawings, which illustrate, diagrammatica l one arrangement of apparatus for carrying out said steps.

In the said drawings, wherein like reference characters are used to indicate like parts in the several views,

Figure 1 is a diagrammatic representation an arran ement of apparatus which may be employe Fig. 2 is a fragmentary portion of the same apparatus, shown on an enlarged scale, and v Fig. 3 is a view similar to Fig. 2, showing Specification 0! Letters Patent.

Application filed March 8, 1915. Serial Roi 11,850.

' specified in the ap if desired, in secur- Patented Apr. 30, 1918.

a modification of the apparatus illustrated therein.

It is to be understood, however, that the carrying out of my invention is not confined to the employment of the herein described, or any other particular arrangement of apparatus, nor to the herein described methods of operating such apparatus, except in so far as pended claims; the drawmgs and description being illustrative merely of one way of applying the principles of my invention.

As heretofore practised, processes of this class, which may or may not involve the complete liquefaction of the working fluid, depending upon the ultimate urpose to which the refrigeration is to e applied, have shown extremely low efliciency and capacity for refrigeration, by reason of the demands made upon the external cooling agency in attaining the desired low temperatures, such systems, therefore, requiring large expenditures of power for su plying the necessary refrigerative effect. 11 suc prior processes it is customar to cool the incoming compressed working uid by interchange of heat with cold expanded working fluid flowing countercurrent thereto, thereby bringing said incoming fluid into a condition to be liquefied by the cooling effect of the external cooling agency. It is known that the-specific heat, and hence the heat absorbing capacity, of a cold compressed gas is greater, the higher the pressure 11 on said gas; in such prior pr0cesses,- there ore, it is apparent that the coolin effect of the expanded low pressure gas owing countercurrent to the incoming ighly compressed gasf is subject to serious limitations by reason 0 this phenomenon; in other words, it is manifestlyiinpossible for a given weight of incoming working fluid under high pressure, to be cooled through the same range of temperature as the same weight of outgoing low pressure as is warmed, by the interchange of heat a ove described. As a result, this deficiency in cooling effect must be compensated for by the external cooling agency, greatly reducing the latters ability to EI'O' uce useful or available refrigerative e ect.

It has heretofore been proposed, in procof this class, to retain the outgoing working fluid under pressure, and even to increase its pressure over the pressure under heat, for the performance of useful work by expansion. However, since the external cooling a ne wh1ch 1s essential to the rocess o sai copending application,

is a one relied upon to effect the liquefaction of the incoming gaseous fluid, a. 6., to remove its latent heat, said liquefaction must be accomplished under such a high pressure, that an increase of pressure su cient to yield any considerable advantage from the above described specific heat henomenon is both impracticable and unesirable.

According to the present invention the difliculties above enumerated are overcome by the employment of certain steps desi to effect the extraction of latent heat rom the incoming working fluid, whereby a at part 0 the burden of cooling heretoore imposed on the external coolin agency is relieved, and the liquefaction o the incoming fluid can be accomplished under a relatively low pressure. As a result of the above, a considerable pressure increase u on the outgoin portion of the working uid is permissi lo; the consequent relatively high heat absorbing capacity of the outgoing fluid can be utilized for the extraction of heat from the low pressure incoming fluid and for absorbing the inleakage of external heat, and the efiiciency and ca acity of the entire system thus correspon ingly increased.

With reference to the application of these rinci les to the attainment of the objects erein fore mentioned, the diagrammatic illustration of one arrangement of apparatus for carryin out the process, together with the severe steps of the process, will now be described in detail.

Referring, by way of example, to the accompanying drawings, the gas dealt with in my rocess is compressed in a compressor 1, and is then led through an ordinary water cooling device 2, for the purpose of extracting the heat of compression therefrom. From the cooling device 2, the compressed gas pa es into a assage 3 of a heat exchan er, designate as a whole by the nu- .mera 4; A portion of the gas in passage 3 is led to an expansion engine 5, expanded therein and returned to the hold end of a second passage 6 of the heat exchan er 4, as shown y the arrows, Fig. 1. Sai ex ansion engine 5 and passage 6 are art 0 an externa cooling agency; the circu ation of a portion of the working fluid through such a ency is utilized in extracting a portion 0 the heat from the incoming compressed a container for a quantlty of the working fluid which is liquefied within said passage in the manner hereinafter set forth; there is no escape for such liquid to the return circuit of the system except through a pump 7, which delivers the liquid into a third passage 8 of the heat exchanger 4 at a pressure higher than the pressure in passage 3. The pressure prevailing obviously due to the resistance imposed against the outflow of vapor from the uper end of said passa e; in forcing liquid into the bottom of this passage, the pump 7 must put it under suflicient pressure to overcome the pressure prevailing therein, which, as above stated, .1s higher than the pressure prevailing in passage 3. The heat exchange between the fluids in passages 3 and 8, in a manner similar to that wellknown in apparatus of this character, en-

tails the discharge of high ressure fluid from the top or warm end 0 assage 8 at substantially the temperature 0 the gas entering the interchanger at the top or warm end of passage 3; the substantial equalize-i tion of temperatures at an given level by heat interchangebetween t e two passages 3 and 8, is contemplated, and in common with other apparatus of this character, the temperatures are lower, the lower the level reached in said interchanger. In said passage 8 the liquid is evaporated and has its temperature raised, in the manner hereinafter particularly described from the passage 8 the highly compressed evaporate may be led, as described in the aforesaid copending application of Jefieries, either with or without the addition of external heat to a motor 9 wherein it may be used to develop a portion of the power for driving the comressor 1. If desired, the gas exhausted rom said motor and the gas from the external cooling agenc leaving the warm end of the passage 6 o the interchanger may be returned to the inlet of the compressor 1, recompressed therein and passed again through the same circui Assuming the establishment of the conditions illustrated in Fig. 1, wherein the broken lines indicate the presence of the working fluid in a liquefied state, which condition-may be attained, if desired, by the operation -of the external cooling agency above described, it will be clearespecially if the fluid dealt with is a simple gas, that the natural interchange of heat between the cold compressed gas at thepoint of liquefaction in passage 3 and the liquid in'passa e 8 will not effect the li uefaction of sai gas in passage 3, .nor an 1 it effect the evaporation of said liquid in passage 8, since the condensation temperature in passage 3 is lower than the boiling temperature in passage 8, owing to the difference in pressure produced by the pump 7. The transfer of the latent heat of condensation from the vapor being condensed above surface a to evaporate the liquid at b, is effected in the manner shown in Fig. 2, wherein 10 represents a coil immersed in the liquid formed within the passage 3 of the interchanger' and 11 represents a pump or compressor interposed between said coil 10 and a coil 12 immersed in the liquid contained within the passage 8 of the interchanger. Said coil 12 communicates with an expander or nozzle 13, and the latter is connected to the inlet side of the coil 10, thereby forming a closed circuit. Said circuit may be supplied with a circulati'ng fluid having a boiling point at the same or a lower temperature than the fluid to be condensed at the surface a. Assuming that the compressor 11 works at. a slightly higher pressure than the pump 7, and that the fluid used in said circuit is the same as the working fluid, it will be clear that the circulation by compressor 11, during a given period, of a weight of fluid equal to or slightly in excess of the weight of working fluid entering passage 3 during the same period, will effect this transfer of heat contents, as follows:-The fluid passing to coil 10, after its pressure is released in nozzle 13, may be mostly liquid, and while condensing the fluid above surface a, by extracting the latent heat of condensation therefrom, it may be only partly evaporated. The mixture of liquid and vapor from the coil 10, passing to the compressor 11, has its pressure and temperature raised by said compressor.

- Passing in substantially gaseous form to the ing thereof, causes its coil 12, it effects the evaporation of liquid at the surface I), by transfer of its heat to said liquid, and is itself condensed thereby, in whole or in part. The subsequent release of pressure from said circulating fluid in the nozzle 13 and the consequent recoolreturn to the coil 10 in condition to repeat the condensation at the surface a, in the manner above described.

The actions, above described, will be carried out, under the conditions assumed, very readily, merel by causing the liquid in coil 10 to be slight y colder thanthe low ressure working vapor to-be liquefied at this point, in order to promote the transfer of heat contents in the'pro er direction; and it will be seen that the di erence in tem erature relied upon to efl'ectthis transfer 0 heat units between the fluids can be made as small as desired simply b increasing the contact surfaces of t e coi The same is obviously true of the action occurring in the high pressure passage 8, in which a slightly higher temperature within the coil 12 insures the necessary exchange of latent heats. It will be clear that other conditions affecting the pressure, temperature, composition, and quantity of the circulatory transfer fluid may be adopted, within a wide range, without departing from the principles.of the actions above set forth, since the foregoing assumptions were made merely for purposes of explanations. As has been shown, the transfer of the relatively large quantities of heat between the working and the circulating fluids occurs in each case with only a very slight temperature difference that is to say, the absorption and rejection of latent heat by the working and circulating fluids, as described above, takes place under substantially constant temperature and hence with the highest possible eflicicncy.

The condensation of the fluid at the surface a is, therefore, secured by an evaporation of circulating fluid in the coil 10, and the evaporation of the liquid at the surface 6 is secured by a condensation of circulating fluid in coil 12. It is apparent that by the proper adjustment of the pressures in the coils 10 and 12, and of the quantity and nature of fluid circulated through said coils by the compressor 11, the relative proportion of liquid and gaseous content of the fluid in said coils may be controlled so as to attain the' most efiicient transfer of latent heat of condensation from the fluid in passage 3 to the liquid in passage 8, namely in such a nianner that the quantity of fluld condensed at a may equal the quantity of liquid evaporated at I).

A modification of the transferring means,

shown in Fig. 3, involves the omission of the coil 12, the fluid from compressor 11 bein discharged directly into the liquid containe in the passage 8. Under these circumstances, only liquid passes to the nozzle 13, while the compressor 11 returns only vapor, which may be at a sufiiciently high temperature to cause the evaporation of an e ual amount of fluid from the liquid at b, w ile being itself com letely condensed.

The return 0 the cold vaporized fluid throu h the passage 8 at a. higher pressure than t e incoming fluid in passage 3, secures a most efficient cooling of said incoming fluid, by reason of the increased specific heat of the returning fluid. Owing to its greater pressure and increased specific heat, said reevaporated fluid carries out from the s stem a greater amount of heat per degree 0 temperature exchanged than is brought in by passage 8 to the liquid in passage 8. The

cooling which must e done by the refrigerating or expansion circuit containing the expansion engine (which is not qualified 5 for the most etficient heat extraction owing to the extremely low pressure of the cold gas returning in passage 6) is reduced to a minimum; however, the drop in temperature in the expansion engine 5, when the latter is suitably constructed, can be made so great as to cause a partial condensation of fluid in the exhaust therefrom which may be collected in the cold end of passa e 6.

The added refrigerative e ect resulting from the process may be utilized in various ways; cold vapor for refri eration may be withdrawn at 14, or liquid may be withdrawn at 15. By means of bypass 16 and valve 17, the liquid in passage 3 may be reduced in pressure and the same may be drawn at 18. v

' It is to be understood that the process, as herein described, does not of necessity entail either the complete or the absolute liquefaction of the aseous working fluid, and that the terms liquefaction, liquid and liquefied as used herein and in the appended claims apply as well to a condition of the fluid where in density and temperature it substantially approaches the liquid state- In such a condition said fluid is susceptible to a pressure increase by the expenditure of an almost negligible amount of power, which, together with the power required for initial compression is largely recoverable in the etiicient manner hereinbefore set fort The same of course holds true with respect to the changes in state undergone b the circulating latent heat transfer flui which, co onding substantially in density and in co dness to the working fluid is comressed by the expenditure of an amount of work which is exceedin ly small in comparison to the work of cooling that would otherout, under pressure wise have to be expended in the external coolin agency to remove the latent heat from t e incoming working fluid.

In the application of the foregoing new principles, which differ radically and essentially from the principles underlying previous processes of this class, it is to be understood that my invention is in no sense limited to e uivalents of the apparatus herein shown, and showing being wholly diagrammatic and illustrative and adopted solely for the pn ose of simplifying the explanation of said roadly new principles.

I claim,

1. In a process of refrigeration, employing a working fluid which is gaseous in its free state, the counter-current circulation of said working fluid to effect heat interchange 5 between heat absorbing and heat rejecting drawn out at 15, or.

portions thereof, and the increase of the capacity of said heat absorbing portion by increase of its specific heat.

2. In a process of the class described, the progressive liquefaction of a fluid which is gaseous in its free state, by the extraction of the latent heat therefrom, and the transfor of said latent heat to the liquefied fluid after the pressure thereon has been raised.

3. In a process of the class described, involving the progressive liquefaction of a fluid which is gaseous in its free state, the raising of the liquefied fluid to a pressure greater than that at which it was liquefied and the vaporization of said liquefied flui under such increased pressure by means of the latent heat of the fluid undergoing liquefaction.

4. In a process of the class described, involving the progressive liquefaction of a fluid which is gaseous in its free state, the raising of the liquefied fluid to a pressure greater than that at which it was liquefied, the vaporization of said liquefied fluid under such increased pressure by means of the latent heat of the fluid undergoing liquefaction, and the circulation of said evaporate in heat exchanging relation to the fluid about to be liquefied.

5. In a process of the class described, the progressive liquefaction of a fluid which is gaseous in its free state, by the compression of said fluid, the expansion of a portion of said compressed fluid, the extraction of latent heat from another portion of sai compressed fluid to liquefy the same, the raising of the pressure on the fluid thus liquefied, the evaporation of the liquefied fluid under such increased pressure by means of said latent heat, and the circulation of said evaporate and said expanded portion of the fluid in heat exchanging relation to the compressed fluid about to be liquefied.

6. In a process of the class described, involving the progressive liquefaction of a fluid which is gaseous in its free state, the raising of the liquefied portion of the flui d to a ressure greater than that at which it was iquefied, and the liquefaction of the gaseous portion under the lower ressure by transfer of its latent heat to said liquefied portion under the higher pressure.

7. In the herein described process of refrigeration, employing a liquefied gas, the extraction of the latent heat of condensation from the gas undergoing liquefaction by heat exchange with a circulating fluid, raising the pressure of said circulating fluid after such extraction, and transferring the extracted heat to the liquefied gas after the pressure on said liquefied gas has been raised.

8. In the herein described process of refrigeration, employing a liquefied gas, the extraction of the latent heat of condensation mass ducing the ressure on said circulating fluid to the initia pressure.

9. In the herein described process of refrigeration, employing a liquefied gas, the

extraction of the latent heat of condensation from the gas undergoing liquefaction by heat exchange with a circulating fluid raising the pressure of said circulating flui after said extraction, and transferring the heat absorbed thereby to the liquid produced by the process after the pressure of said 1i uid has been raised.

10. The herein described process of refrigeration, comprising the extraction of latent heat from a fluid under oing condensation by heat exchange wit an independent circulating fluid, and the transfer of said latent heat to the first fluid at higher pressure undergoing evaporation. escri 11. The herein ed process of refrigeration, comprising the extraction of latent heat from a fluid, at a low temperature, by heat exchan c with an independent circulatin fluid, an the transfer of said extracted eat to the first fluid at a higher temperature.

12. The herein described process of refrigeration, comprising the extraction of latent heat from a fluid undergoing condensation by heat exchange with a circulating fluid, and the transfer of said latent heat to the first fluid at a higher pressure undergoing evaporation.

13. The herein described process of refrigeration, comprising the'extraction of latent "heat from a fluid, at a low temperature, by

heat exchange with a circulating fluid, and

the transfer of said extracted heat to the first fluid at a higher temperature.

14. The herein described process of refrigeration, comprising the extraction of latent heat from a fluid "at a low temperature, and the transfer of said extracted heat to said fluid at a higher temperature, by interchange of heat, with a circulating fluid which undergoes changes of pressure, and

whose boiling point at the lower pressure is at a lower temperature than the fluid from which heat is extracted, and whose condensing point at the higher pressure is at a higher temperature than the fluid to which the heat is added.

15. In a process of the class described, involving the progressive liquefaction of the} fluid which is aseous in its free. state, the raising of the iquefied fluid to a ressure greater than that at which it was liquefied,

and the transfer of latent heat of condensation from the gaseous portion undergoing liquefaction to said li uefied portion under the increased pressure y the circulation of a fluid in heat exchanging relation to said two portions.

16. In a process of the class described, involving the progressive liquefaction of a fluid which is gaseous in its free'state, the raising of the liquefied fluid to a ressure greater than that at which it was liquefied, and the transfer of latent heat of condensation from the gaseous portion undergoing liquefaction to said liquefied portionjunder the increased pressure by the alternate comression and expansion of a fluid circulated in heat exchanging relation to said two portions.

17. In a process of the class described, involving the progressive liquefaction of a fluid which is aseous in its free state, the raising of the iquefied fluid to a ressure greater than that at which it was 11 uefied, the vaporization of said liquefied flui under such increased pressure by means of the latent heat of the fluid undergoing liquefaction, and the utilization of the vapor thus produced to furnish power.

18. In a process of the class described, involving the progressive liquefaction of a fluid which is aseous in its free state, the raising of the iquefied fluid to a ressure greater than that at which it was 11 uefied, the vaporization of said liquefied flui under such increased pressure by means of the latent heat of the fluid undergoing liquefaction, the circulation of said eva orate in heat exchanging relation to the uid about to be liquefied, and the expansion of said evaporate to produce power.

19. In a process of the class described, extracting latent heat from a fluid under 0- mg l1quefaction by means of another fluid raising the pressure on the liquefied fluid and on the second fluid, and circulating said second fluid under its increased pressure in heat exchangin relation to the high pressure liquefied uid.

'20. In a process of the class described, extractrng latent heat from a fluid under 0- mg l1quefact1on by means of another fluid raising the pressure on the liquefied fluid and on the second fluid, circulating said second fluid under its increased pressure in heat exchangiuag relation to the high pressure l1quefie uid, to evaporate the latter, and expanding said evaporate in an expansion engine. a

21. In a process of the class described, extractmg-latent heat from a fluid undergoinga liquefaction by means of another fluid,

vaporizing the liquefied fluid, by means of said other fluid, under a suflicient pre's sure to enable the evaporate to perform useful work by expansion.

22. In a process of the class described, extracting latent heat from a fluid undergoing liquefaction by means ofanother fluid, vaporizing the liquefied fluid by means of said other fluid, under a suflicient pressure to enable the evaporate to absorb heat usefully,

and expanding said evaporate in an expansion engine.

23. In a process of the character set forth,

employing a working fluid which is gaseous in' its free state, the passage of said fluid through the liquid state, and the transferv of latent heat from the gaseous working fluid to the portion thereof which is in the liquid state.

24. In a process of the character set forth the passage of a gaseous working fluid throu h the liquid state, the increase of pressure t ereon while in the liquid state, and the transfer of latent heat from the gaseous 20 fluid to the liquid whose pressure has been FRED E. NORTON. Witnesses PENELOPE OOMBERBAGH, NELIJE WHALEN.

' raised.

Correction in Letters Patent No. 1,264,845.

It is hereby certified that in Letters Patent No. l,264,845, granted April 89,

1918, opon the applieation of Fred E. Norton, of Worcester, Meesaehxisetts, for

an improvement in "Processes of Refrigeration, on error eppears in the speoifioetion requiring correetion as follows: Page 2, line 58, for the word hold.

read 0016; and that the said Letters Patent should be read with this correction therein that the same mej conform to the record of the case in the Patent Signed, end sealed this 4th day of June, A. 1)., 1918.

' tsfihrh] Acting 01PM.

- one-115. 

